you will need the drivers for the Trident display controller chip to get the display to go to 800X600 in windows. the display looks bad in 640X480.
you will need the drivers for the VIA chipset to get the USB and sound to work correctly.
you will need the modem driver if you want to use that. while the modem is inside the i-o case, it is connected to a serial port as an external modem. windows does not automatically detect it.
if your i-o has the RISE cpu, the sound will not work under windows as windows sound on the i-o needs MMX. an Intel 200MMX cpu is a straight replacement for the RISE.
you will need a keyboard/mouse adapter cable, similar to the cable to connect a keyboard/mouse to an IBM Thinkpad, to connect a real ps/2 type keyboard.
you will need the ps/2 keyboard to get into the bios cmos setup with an 'escape' key.
when you set up your hard drives make sure they are active and bootable to a c:\> command prompt before installing them in the i-o's.
when you get together all drivers and software you need to run the machine, copy your win98 folder from your installation CD and everything else to the h.d. before installing the h.d. in the machine.
before installing any software, go into the bios cmos setup and where it allocates an IRQ for the display and disable the display IRQ. in 'BIOS FEATURES SETUP', change the boot device to device c. in 'Standard CMOS Setup', set the hard disk type to 'auto' and mode to auto'. you do not need to do 'IDE HDD AUTO DETECTION'.
do the os and driver installation with the h.d. in the i-o. some people install everything on the h.d. with the h.d. running on a different machine and then move the h.d. to the i-o, let windows recognize the different hardware and go from there. this makes more work.
after you install win98, install the VIA drivers.
then go into My Computer/Control Panel/System/Device Manager/hard disk controllers/settings and change the 'dual IDE Channel Controller to "Only Primary Channel Enabled". you will only have one ide channel in the i-o, and you will need the IRQ.
then install the display driver. go back to My Computer/Control Panel/Display/Settings an set up the display to 800X600 etc.
then install the modem driver and set up the modem.
these should be done in this order or you may have problems getting things to work correctly.
after you get one i-o running the way you want, you can do everything again on the other or take the h.d. out and copy it to the h.d. for the second i-o. if you drag and drop from one h.d. to the other, you should have the second h.d. an exact copy of the first, ready to install and run. i even keep a backup mirror copy of my i-o h.d. on my desktop computer.
your i-o setup just got complicated. do searches on this board for where to get the chipset and modem drivers. if you run into a problem, come back and ask.
remember, have fun